Children today are at risk of exposure to multiple environmental hazards - toxic chemicals, social stressors and the hazards of the built environment. Evidence is mounting that exposures in the environment contribute to causation of many common pediatric diseases, and also that they may increase risk for disease in adult life. Yet despite the potential importance of the environment to human health, few pediatricians are trained to study, diagnose, treat or prevent disease of environmental origin, and few academic health centers have programs in environmental pediatrics or research leaders trained to direct such programs. The IOM states that there is national need to expand the scientific workforce in environmental medicine. To train the next generation of physician-researchers and academic leaders in environmental pediatrics, the Mount Sinai School of Medicine seeks support for a 3-year, post-residency interdisciplinary research training program targeted to clinically trained pediatricians. Epidemiological research in environmental pediatrics will be the core training theme. Diseases of principal focus will be neurodevelopmental disorders;diabetes and obesity;and asthma and allergy. We intend to provide our fellows with a robust methodological base and to equip them with a versatile set of tools that they can apply to study a wide range of scientific questions in environmental pediatrics. Selection of fellows will be competitive, and emphasis will be placed on recruitment of underrepresented minorities. In year 1, fellows will receive didactic training in epidemiology, biostatistics, environmental medicine, study design and research methodology. A seminar series in molecular epidemiology and a course on grant writing will complement the core curriculum. In years 2 and 3, emphasis will be placed on a mentored research project. Fellows will gain clinical experience in environmental pediatrics in the Pediatric Environmental Health Specialty Unit. A mentor and 1-2 additional faculty members will guide each fellow. Each fellow's progress will be evaluated semi-annually. Expected outcomes include: authorship of at least 1-2 manuscripts based on original research;authorship of at least 2- 3 posters and/or abstracts for presentation at regional or national meetings;successful completion of an MPH degree focusing on environmental health;development in year 3 of a K08 or R01 grant proposal;and evidence of transition toward independent investigator status. An Executive Faculty Committee and an External Advisory Board have been established to guide the program. This program builds on a fellowship in Pediatric Environmental Health supported at Mount Sinai since 2002 by the Ambulatory Pediatric Association. It links to a Center for Children's Environmental Health and Disease Prevention Research;a Pediatric Environmental Health Specialty Unit;and a recently established Vanguard Center for the National Children's Study.